A number of mechanisms exist for communicating with computers. Some communication mechanisms include keys pad and mouse inputs. Also, touch pads and touch screens are used in laptops and mobile tablets.
Some systems track human movement for communication with computers. For example, a camera may be used to detect hand gestures made by a user. A computer may interpret these hand gestures as commands. Some systems use multiple cameras to detect the three dimensional location of the hands at the time the hand gestures are made. Inputs from each of the cameras may be integrated together for the computer to determine the hand's location.